Window lock



Dec. 27, 1927.

' J. E. BERGONZONI wmhuw LOCK Filed May 24, 1927 Patented Dec. 2'7, 1927.

UNlTED srArEs I PATENT OFFICE.

illlSEPI-I E. BERGONZONI, F NEWTON, MASSACHUSETTS, ASSIGNQR OF ONE-HALF TO WALTER D. DUNN, OF BELMONT, MASSACHUSETTS.

WINDOW LOCK.

Application filed May 24, 1927. Serial No. 193,924.

This invention relates to window locks and more particularly to looks of the mag netic type in which the plunger which inter locks the window sash with the window a frame is retracted or advanced by a magnet.

Objects of the invention are to provide a window lock which is entirely concealed, which may be operated near the window or at a remote location, which is constructed to and arranged to operate on low voltage circuits such as ordinary bell circuits of a few volts, which is easy to construct and durable in use, and which will not only operate on low voltage but is positive and reliable in action.

A cardinal feature of the invention consists in the use of a locking plunger which extends into the electromagnet and which is formed of diamagnetic' material either 91% wholly or at least that portion which extends into the electromagnet so that this portion cannot become magnetized, whereby the plunger has no tendency to stick in the magnet and is therefore more reliable in action, Moreover, since the plunger is entirely released from the action of the electroma-gnet when the magnet is ole-energized,

a very light spring is sufficient to advance the plunger to locking position; and, by

using a very light spring, the current required to retract the plunger when the magnet is energized is very small. so that the device may be operated by current of low voltage such as is found in the bell circuits of house wiring systems. By employing current of. such low voltage the wiring need not be enclosed in pipes or cables and the cost of the wiring is thereby greatly reduced.

For the purpose of illustration a concrete embodiment of the invention is illustrated the accompanying drawing, in which:

l is a longitudinal section of the lock applied to a window;

Fig 9, is a face view of the loch; and

llig, 3 is a central longitudinalsection of the loclring plimger and actuating mocha the particular embodiment of the invention illustrated in the figures, A reprerents the window frame and B the window The lock; con iprises a casing it set into reset E2 in the frame A and a face plate 3 fast to the casing 1 and mounted flush with taco of the frame A. "the window sash B is provided with a recess to receive the locking plunger when it is advanced to locking position and this opening is preferably fitted with a metallic socket member l slightly larger than the locking plunger 5. The locking plunger occupies the position shown in Fig. 1 when the window is locked and the position shown in Fig. 3 when it is retracted to unlocked position. i

v The magnet for operating the locking plunger comprises a core 6 of iron or other suitable material, disks or rings 7 and 8 fast on the core, and a winding 9 on the core between the end rings. The magnet may be mounted on the casing 1 by means of a screw 1J0 threaded intothe end of the core memer 6. v

In the preferred embodiment of the invention illustrated in the drawings, the locking plunger 5 has a rear portion 11 of reduced diameter adapted to "slide loosely in the core member 6. The armature 12 is mounted on the plunger at the junction between the portions of different diameters, the armature being secured in any suitable manner as by welding or brazing or a pressed lit. While the armature 12 is formed of para magnetic material such as iron, the plunger, or at least the portion 11 of reduced diameter which extends into the core of the magnet, is preferably formed of brass or other diamagnetic material so that it does not become magnetized and therefore does not tend to stick in the magnet after the magnet is deenergized. A spring 13 is provided in the core member to advance the plunger to locking position when the magnet is deenergized.

The magnet may be connected in any suit able circuit, as for example, when employing locks on a plurality of windows, a switch may be associated with each lock for operatlltl ing the lock of the associated window nd a; 1

master switch may be provided to actuate all of the locks of a plurality of windows.

By forming the plunger of diamagnetic material so that the plunger has no tendency to sticli; in the magnet when the magnet is (ls-energised a very light spring may be employed at 13 to advance the plunger into locking position when the magnet is deencrgiaed. And, owing to the fact that a light spring may be employed, a weak cur-- rent is suflicicnt to retract the locking llll) llllli plunger against the action of the spring, whereby the devicemay be operated on a few volts such as low voltage bell circuits.

I claim:

1. A window lock comprising a casing constructed to be mounted in a window frame, a plunger movable through the face of the casing for engagement with the window sash, an electromagnet in the casing having a hollow paramagnetic core, and a coiled compression spring in said core, said plunger being formed of diamagnetic material and having a ring of paramagnetic material extending over the end of said core.

2. A window lock comprising a casing constructed to be mounted in a window frame, a plunger movable through the face of the casing for engagement with the window sash, an electromagnet in the casing having a hollow aramagnetic core, and a coiled compresslon spring in said core, said plunger having 'a diamagnetic portion extending into said core against said spring and a paramagnetic portion extending laterally over theend of said core.

3. A window lock comprising a casing constructedto be mounted in a window frame, a plunger movable through the face of the casing for engagement with the window sash, an electromagnet in the casing having a hollow paramagnetic core, and a coiled compression spring in said core, said plunger iavinga diamagnetic portion extending into said core against said spring and a paramagnetic portion near the end of said magnet.

' 4. A window lock comprising a casin constructed to be mounted in a window rame, a plun er movable through the face of the casing or engagement with the window sash, a spring for advancing the plunger, and an electromagnet in the casing for retracting the plunger, the plunger being formed of diamagnetic material and having a ring of paramagnetic material extending over the end of the magnet.

5. A window lock comprising a casin constructed to be mounted in a window rame, a plunger movable through the face of the casing for engagement with the window sash, a spring for advancing the plunger, and an electromagnet in the casin for retracting the plunger, the plunger iaving a diamagnetic portion extending into said core and a paramagnetic portion extending laterally over the end of the magnet.

Signed by me at Boston, Massachusetts, this 18th day of May, 1927.

JOSEPH E. BERGONZONI. 

